Fuel delivery unit for a motor vehicle

ABSTRACT

A fuel delivery unit for a motor vehicle, wherein a swirl pot has a base formed from an upper part and a lower part, and an outer wall connected to the base, forming a seal. The upper part and the lower part bound fuel-delivering regions of a suction jet pump and of a section of a feed line. This arrangement allows the fuel delivery unit to be produced at particularly low cost.

The invention relates to a fuel delivery unit for a motor vehicle,having a fuel pump, which is arranged in a swirl pot, for deliveringfuel from the swirl pot into a feed line, having a suction jet pump fordelivering fuel into the swirl pot, having a propellant line which leadsfrom the fuel pump to a nozzle of the swirl pot, and having a mixingtube, which opens out into the swirl pot, of the suction jet pump, withthe swirl pot having a casing which is fastened to a base.

Fuel delivery units of said type are frequently used in modern motorvehicles and are known from practice. In the known fuel delivery units,individual components are inserted into the swirl pot, which is usuallyformed in one piece, and are connected to one another. A port, whichprojects away from the fuel pump, for a feed line usually projects outof the swirl pot. However, since a fine filter which is arranged in thefeed line is often arranged within the swirl pot, the feed line from thefuel pump is guided back into the swirl pot again to the fine filter.Furthermore, a branch is usually guided from the feed line to thesuction jet pump which is provided for filling the swirl pot. This leadsto a very large installation space of the known fuel delivery unit andto complex assembly.

The invention is based on the problem of refining a fuel delivery unitof the type specified in the introduction in such a way that said fueldelivery unit is of particularly simple and compact design.

Said problem is solved according to the invention in that the base hasan upper part, which faces toward the fuel pump, and a lower part, whichfaces away from the fuel pump, in that the upper part and lower part aresealed off with respect to one another and in that fuel-guiding regionsare arranged between the upper part and the lower part of the base.

By means of said design, it is possible for partial regions offuel-guiding regions, such as of the lines, to be arranged within thebase of the swirl pot. On account of the invention, the upper part andthe lower part form preferably shell-shaped components which receivesections of the lines. Said lines therefore need no longer be mountedseparately. Components projecting from the swirl pot can be easilyavoided in this way. Furthermore, by means of a correspondingarrangement of the parting plane in the base, it is possible for theupper part and lower part to be produced in each case as axiallydemoldable injection-molded parts.

The fuel delivery unit according to the invention is of particularlysimple structural design if the fuel-guiding regions of the base have asection, which leads from the fuel pump to the fine filter which isarranged in the swirl pot, of a feed line, with the section of the feedline being delimited partially by the upper part and the lower part ofthe base. The upper part and the lower part are preferably each formedin the manner of a half-shell and bear against one another so as todelimit the section of the feed line. This contributes to a particularlycompact design of the fuel delivery unit according to the invention.

To further simplify the structural design of the fuel delivery unitaccording to the invention, it is expedient if the fuel-guiding regionsof the base have the mixing tube of the suction jet pump, with themixing tube being formed partially by the upper part and by the lowerpart. The upper part and the lower part are preferably each formed inthe manner of a half-shell and bear against one another so as to delimitthe mixing tube. This contributes to a particularly compact design ofthe fuel delivery unit according to the invention.

To further reduce the number of components of the fuel delivery unitaccording to the invention, it is expedient if the upper part of thebase and the casing seal off a fine filter which is arranged in theswirl pot.

According to another advantageous refinement of the invention, thestructural expenditure for the precise alignment of the components ofthe base plate can be kept particularly low if the upper part and thelower part of the base each have annular edges which bear against oneanother. The upper part and the lower part preferably have positivelylocking surfaces which correspond to one another and by means of whichsaid upper part and lower part engage into one another in a positivelylocking manner.

To further simplify the alignment of the components of the swirl pot, itis expedient if at least one of the edges of the upper part or of thelower part is sealed off with respect to the casing of the swirl pot.The base of the swirl pot is also reliably sealed off in this way.

The mixing tube of the suction jet pump could for example open out intoa chamber, which is closed off by means of a base valve, of the swirlpot. However, to further reduce the number of components of the fueldelivery unit according to the invention, it is expedient if the mixingtube is sealingly connected to a riser tube which is formed in one piecewith the casing of the swirl pot and if the riser tube extends into aregion, which is remote from the base, of the intended maximum fillinglevel of the swirl pot. As a result of said design, the swirl pot doesnot require a base valve, since the length of the riser tube limits thefilling level in the swirl pot. Since the riser tube is arranged on thecasing of the swirl pot and extends over a partial region of the heightthereof, the swirl pot can be produced together with the riser tube in aparticularly cost-effective manner in an axially demoldable injectionmold.

According to another advantageous refinement of the invention, tofurther reduce the number of components of the fuel delivery unitaccording to the invention, it is expedient if a section, which leadsaway from the fine filter, of the feed line is formed in one piece withthe casing of the swirl pot.

The assembly of the fuel delivery unit according to the invention isparticularly simple if ports of the nozzle of the suction jet pump andof the section of the feed line, which leads from the fuel pump to thefine filter, are aligned perpendicular to the surface of the base of theswirl pot. As a result of said design, the fuel pump can be pluggedaxially onto the ports in a simple manner, and is thereby fully mounted.Here, a suction port of the fuel pump preferably opens out into the baseregion of the swirl pot.

The invention permits numerous embodiments. To further clarify its basicprinciple, one of said embodiments is illustrated in the drawing and isdescribed below. In the drawing:

FIG. 1 schematically shows a fuel supply device for an internalcombustion engine of a motor vehicle having a fuel delivery unitaccording to the invention.

FIG. 2 shows a sectioned illustration of the fuel delivery unitaccording to the invention from FIG. 1, and

FIG. 3 shows, on a greatly enlarged scale, a sectioned illustration of abase of a swirl pot of the fuel delivery unit according to the inventionfrom FIG. 1.

FIG. 1 schematically shows a fuel delivery unit 2, which is arranged ina fuel tank 1 of a motor vehicle, for delivering fuel to an internalcombustion engine 3 of a motor vehicle. The fuel delivery unit 2 sucksin fuel from the base region of the fuel tank 1 and delivers said fuelinto a feed line 4 which leads to the internal combustion engine 3.

FIG. 2 shows, on a greatly enlarged scale, a sectioned illustration ofthe fuel delivery unit 2 from FIG. 1 with an electrically operated fuelpump 6 which is arranged in a swirl pot 5. A fine filter 7 is alsoarranged in the swirl pot 5. The swirl pot 5 has a base 9 which isconnected to a casing 8. The base 9 and the casing 8 seal off the finefilter 7. The base 9 also has a suction jet pump 10. The suction jetpump 10 is supplied with fuel as propellant by the fuel pump 6, sucksfuel out of the surroundings of the swirl pot 5 and delivers said fuelinto the swirl pot 5. For this purpose, the suction jet pump 10 has anozzle 11 which is connected to the fuel pump 6. The casing 8 of theswirl pot 5 is connected in one piece to a riser tube 12. The riser tube12 is connected to a mixing tube 13, which is arranged in the base 9, ofthe suction jet pump 10. A section 14 of the feed line 4 from the fuelpump 6 to the fine filter 7 also leads through the base 9. A furthersection 15, which is arranged downstream of the fine filter 7 in theflow direction, of the feed line 4 is formed in one piece with thecasing 8 of the swirl pot 5.

FIG. 3 shows, on a greatly enlarged scale, the base 9 of the swirl pot 5from FIG. 1. Here, it can be seen that the base 9 has an upper part 16and a lower part 17 which is sealingly connected to the upper part 16.The upper part 16 and the lower part 17 form in each case one part ofthe mixing tube 13 of the suction jet pump 10 and that section 14 of thefeed line 4 which leads from the fuel pump 6 to the fine filter 7. Ports18 of that section 14 of the feed line 4 which is arranged between thefuel pump 6 and the fine filter 7 and of the suction jet pump arealigned perpendicular to the surface on the base 9, such that the fuelpump 6 illustrated in FIG. 2 can be easily plugged on in order to bemounted. Furthermore, FIG. 3 shows that the upper part 16 and the lowerpart 17 of the base 9 each have annular edges 20, 21 which bear againstone another. The edges 20, 21 are sealed off with respect to the casing8, illustrated in FIG. 2, of the swirl pot 5.

1.-9. (canceled)
 10. A fuel delivery unit for a motor vehicle,comprising: a swirl pot casing forming a swirl pot; a fuel pump arrangedin the swirl pot, the fuel pump configured to deliver fuel from theswirl pot into a feed line; a suction jet pump configured to deliver thefuel into the swirl pot, the suction jet pump comprising: a nozzle; apropellant line coupled between the fuel pump and the nozzle; and amixing tube coupled to the nozzle, the mixing tube feeding the fuel intothe swirl pot; a base section fastened to the swirl pot casing, the basesection comprising: an upper base part that faces toward the fuel pump;and a lower base part that faces away from the fuel pump, wherein atleast one of the mixing tube, the propellant line, and the nozzle isarranged between the upper base part and the lower base part.
 11. Thefuel delivery unit according to claim 10, further comprising: a finefilter arranged in the swirl pot; and a fuel-guiding region in the basecoupled between the fuel pump and the fine filter, the fuel-guidingregion being delimited partially by the upper base part and the lowerbase part.
 12. The fuel delivery unit according to claim 10, wherein themixing tube is formed partially by the upper base part and by the lowerbase part.
 13. The fuel delivery unit according to claim 11, wherein theupper base part and the casing form a compartment for the fine filter.14. The fuel delivery unit according to claim 10, wherein the upper basepart and the lower base part each have annular edges configured to bearagainst one another.
 15. The fuel delivery unit according to claim 14,wherein at least one of the edges of the upper base part or of the lowerbase part is sealed to the casing.
 16. The fuel delivery unit accordingto claim 10, wherein the mixing tube is connected to a riser tube formedin one piece with the casing, the riser tube extending into a region ofthe swirl pot remote from the base to an intended maximum filling levelof the swirl pot.
 17. The fuel delivery unit according to claim 11,wherein a line section that leads away from the fine filter is formed inone piece with the casing.
 18. The fuel delivery unit according to claim11, wherein ports of the nozzle of the suction jet pump and of thefuel-guiding region, are substantially perpendicular to a surface of thebase that faces toward the fuel pump.
 19. The fuel delivery unitaccording to claim 10, wherein at least one of the upper base part andthe lower base part are axially demoldable injection molded parts.